Propeller



J. CARPENTER.

PROPEL LER.

APPLICATION FILED JULY 22,1918.

Patented Dec. 5,1922.

awwwto'p John Cizrpenizg Patented Dec. 5, 1922.

PROPELLER.

Application filed July 22,

To all whom it may concern.

Be it known that I, J'oHN CARPENTER, a citizen of New Zealand, residingat North Auckland, New Zealand, have invented new and usefulImprovements in Propellers, of

which the following is a specification.

This invention relates to screw propellers and it has for its object toproduce a propeller of simple and improved construction, the blades orflukes of which have bearing faces of great area, whereby the operationof the device will be rendered particularly effective.

A further object of the invention is to produce a screw propeller, theblades or flukes of which are spirally disposed with respect to the hubor axis of rotation, said blades or flukes extending at each enduninterruptedly beyond the corresponding end of the hub, therebyincreasing the effective operating area of the blades. 1

With these and other ends in view which will readily appear as thenature-of the invention is better understood, the same consists in theimproved construction and novel arrangement and combination of partswhich will be hereiaf ter fully described and particularly pointedout inthe claim.

In the accompanying drawing has been illustrated a simple and preferredform of the invention, it being, however, understood that nolimitationis necessarily made to the precise structural details thereinexhibited, but that changes, alterations and modifications within thescope of the claim may be resorted to when desired.

In the drawing, v

Figure 1 is a side view of a propeller constructed in accordance withthe invention.

Figure 2 is an end view of the same. Figure 3 is a transverse sectionalview taken on the line 33 in Figure 1.

Corresponding parts in the several figures are denoted by likecharacters of reference. The improved propeller includes a longrtudinalcentral portion 15 which constitutes a hub, said central portion havinga bore 16 formed longitudinally thereon, and trans-.

verse threaded openings 17 being also pro- 1918. Serial m.- 246,243.-

vided for the reception of fastening members, such as screws 18, wherebythe device -may be securely mounted on a revoluble shaft 19.

Formed on opposite sides of the hub 15 are blades or flukes 20 which arespirally disposed, each of said blades making a half s iral convolutionwith respect to the hub.

ach of the blades or flukes is of a length materially exceeding, thelength of the hub, said blades having rounded end portions 21 whichextend uninterruptedly beyond the ends of the hub, thereby materiallyincreasing the effective area'of the blades.

In the construction of the improved propeller it will be noted that thesame is preferably formed of single casting, and that the diameter ofthe hub does not exceed the thickness of the blades or flukes at thejuncture of said blades or flukes with the hubs, the blades or flukesbeing tapered from the hub and outwardly to a thickness which will notexceed that which is necessary to produce the requisite strength. Theresult of this'construction will be that the spiral grooves orconvolutions formed by the respective blades or flukes will be smoothand uninterrupted throughout and free from any projections that would beliable to form any resistance to the operation of the device.

From the foregoing description taken in connection with the drawing itwill be readily understood that the improved propeller may be readilyapplied to the propulsion of any fioating craft, and that the operationthereof will be equally effective without regard to the direction ofrotation.

What is claimed is A propeller comprising an elongated hub portion, anda pair of spiral blades projecting from-opposite sides thereof andcorrespondingly arranged, the ends of the blades projecting materiallybeyond the ends of the hub portion with all the extremities of thebladesbeing-semi-circular in shape.

In testimony whereof I afiix my signature. I

JOHN CARPENTER.

